Feedthrough capacitance compensation for resonant devices

A device having an input node to receive an input signal and an output node to provide an output signal, the device comprising:

• a resonator coupled to the input and output nodes, characterized by a transducer to drive the output node, and further characterized by a feedthrough capacitance such that portions of the input signal bypass the transducer to allow a spurious signal to reach the output node;
• a compensation capacitor coupled to the output node to define a compensation capacitance in accordance with the feedthrough capacitance;
• and,
• a phase inversion circuit coupled to the compensation capacitance to generate a compensation signal and coupled to the output node such that the spurious signal is offset by the compensation signal;
• wherein the compensation capacitor is configured such that the compensation capacitance is below the feedthrough capacitance such that the compensation signal and the spurious signal are unmatched to avoid overcompensation.

A device having an input node to receive an input signal and an output node to provide an output signal, the device comprising:

• a parallel array of resonators comprising a resonator coupled to the input and output nodes, the resonator characterized by a transducer to drive the output node, and further characterized by a feedthrough capacitance such that portions of the input signal bypass the transducer to allow a spurious signal to reach the output node;
• a parallel set of compensation capacitors to offset a respective feedthrough capacitance of each resonator in the array, the set comprising a compensation capacitor coupled to the output node to define a compensation capacitance in accordance with the feedthrough capacitance;
• and,
• a phase inversion circuit coupled to the compensation capacitance to generate a compensation signal and coupled to the output node such that the spurious signal is offset by the compensation signal;
• wherein the compensation capacitor is configured such that the compensation signal and the spurious signal are unmatched to avoid overcompensation.

A device having an input node to receive an input signal and an output node to provide an output signal, the device comprising:

• a differential amplifier coupled to the input and output nodes;
• a resonator disposed in a first feedback path of the differential amplifier and characterized by a transducer to drive the output node, and further characterized by a feedthrough capacitance such that portions of the input signal bypass the transducer to reach the output node;
• and,
• a compensation capacitance disposed in a second feedback path of the differential amplifier separate from the first feedback path to offset the feedthrough capacitance;
• wherein the first and second feedback paths are configured in a differential input scheme.

A device having an input node to receive an input signal and an output node to provide an output signal, the device comprising:

• a differential amplifier coupled to the input and output nodes;
• an array of resonators comprising a resonator disposed in a first feedback path of the differential amplifier and characterized by a transducer to drive the output node, and further characterized by a feedthrough capacitance such that portions of the input signal bypass the transducer to reach the output node;
• and,
• a set of compensation capacitances to offset a respective feedthrough capacitance of each resonator in the array, the set comprising a compensation capacitance disposed in a second feedback path of the differential amplifier separate from the first feedback path to offset the feedthrough capacitance;
• wherein each resonator of the array is disposed in parallel with the first feedback path and each compensation capacitance of the set is disposed in parallel with the second feedback path.